Garden Talk: August 12, 2010

From NGA Editors

A Cold Shower for Hot Tomatoes

We all know that tomato plants growing in the garden are heat-lovers. So it may come as a surprise to find that, for young plants, using cold irrigation water results in the sturdiest plants.

Recent research in Taiwan found that seedlings watered with 41?F water had sturdier stems, increased dry weight and higher concentrations of chlorophyll and were more compact than ones watered with 50?F or 59?F water. Cold water irrigation was begun when the seedlings were about an inch high and continued either every day or every other day for three weeks.

Previous trials showed that cold water irrigation produced more compact cabbage seedlings, and researchers speculate that this technique could be used with similar effect on a variety of seedlings.

ADHD and Pesticide Exposure- A Possible Link

If you need a reason to consider "going organic" in the garden and at the supermarket, consider the findings of a study published recently in Pediatrics?, the official journal of the American Academy of Pediatrics. Using data on more than 1000 children 8 to 15 years of age in the U.S., researchers found that children with higher levels of urinary metabolites of organophosphate pesticides were about twice as likely to meet the diagnostic criteria for attention-deficit hyperactivity disorder (ADHD) as those with very low concentrations of the metabolites.

Children are especially vulnerable to organophosphate toxicity because of the susceptibility of their developing brains and their low body weight relative to the amount of pesticide exposure. And how does this exposure come about? According to the EPA, food, drinking water and residential use are all important sources of exposure, but diet is the most important source for infants and children, according to the National Academy of Sciences. Consider that the U.S. Pesticide Data Program's 2008 Report found detectable concentrations of the organophosphate pesticide malathion in 28% of frozen blueberries sampled, 25% of strawberries and 19% of celery.

While noting that more research is needed to establish whether this association is causal, the researchers concluded that "Our findings support the hypothesis that current levels of organophosphate pesticide exposure might contribute to the childhood burden of ADHD."

Wave Good-bye to Wasps

Nothing can spoil a late summer picnic or barbecue faster than having to fend off hordes of wasps and yellowjackets. But hold that spray- wasps are also beneficial garden predators that feed on pests such as gypsy moth caterpillars. For a simple, pesticide-free and environmentally friendly way to discourage paper wasps, try the Original Waspinator? from Contech. Since these wasps are territorial, this device, which looks like a wasps' nest, sends the message to passing wasps to stay away because the territory is already claimed. It's easy to hang this portable deterrent wherever it's needed- take it to the backyard, beach or park.

While many species of yellowjacket wasps are also beneficial predators, some species are scavengers and it is these that are likely to be bothersome around picnic tables, garbage cans and other food sources. To discourage them in your yard, keep garbage can lids tightly closed, don't keep pet food in dishes outside and cover food and sugary drinks that are sitting outside. Also make sure your compost bin is covered or located away from areas of the yard where people eat and play.

To protect the area around a picnic table or play area, hang Contech's Wasp and Yellowjacket Bag Trap. Its non-toxic, pesticide-free lure draws yellowjackets and wasps into the trap and keeps them there. According to the company, the trap's field-tested new design has an improved catch rate and uses 50% less material in its packaging.

The Year of the Heirloom Apple

As apple harvest season approaches, take a moment to consider that 'Delicious' apples account for 41% of the apple crop in the U.S., and only 11 varieties comprise 90% of the apples sold in chain grocery stores in this country. This lack of diversity troubles the organization Renewing America's Food Traditions (RAFT) Alliance, which has designated 2010 as the Year of the Heirloom Apple. Concerned about the loss of genetic diversity in apples, as well as the loss of traditional knowledge of apple culture, RAFT Alliance has proposed that ninety endangered antique and heirloom apple varieties in each of the regions of the country with the highest surviving apple diversity- the Great Lakes, New England and Appalachia- be targeted for recovery.

To help accomplish this, they have published Forgotten Fruits Manual and Manifesto: Apples, available as a download from their website. This 31 page publication begins with a brief history of apple diversity in this country, addresses the factors contributing to the loss of apple varieties and concludes with suggestions for ways to help restore diversity in apple production.

So if you plan on planting apples in your home garden, consider including some of the delicious antique and heirlooms varieties adapted to your area. And support those growing these diverse selections commercially when you buy fruit at farmers markets, orchards, CSAs and markets.